Atanasoff-Berry Computer (ABC), an early digital computer. It was generally believed that the first electronic digital computers were the Colossus, built in England in 1943, and the ENIAC, built in the United States in 1945. However, the first special-purpose electronic computer may actually have been invented by John Vincent Atanasoff, a physicist and mathematician at Iowa State College (now Iowa State University), during 1937–42. (Atanasoff also claimed to have invented the term analog computer to describe machines such as Vannevar Bush’s Differential Analyzer.) Together with his graduate assistant Clifford E. Berry, Atanasoff built a successful small prototype in 1939 for the purpose of testing two ideas central to his design: capacitors to store data in binary form and electronic logic circuits to perform addition and subtraction. They then began the design and construction of a larger, more general-purpose computer, known as the Atanasoff-Berry Computer or the ABC.

Clifford Berry and the Atanasoff-Berry Computer. The ABC, c. 1942, was possibly the first …

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Various components of the ABC were designed and built from 1939 to 1942, but development was discontinued with the onset of World War II. The ABC featured about 300 vacuum tubes for control and arithmetic calculations, use of binary numbers, logic operations (instead of direct counting), memory capacitors, and punched cards as input/output units. (At Atanasoff’s invitation, another early computer pioneer, John Mauchly, stayed at Atanasoff’s home and was freely shown his work for several days in June 1941.)

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It was generally believed that the first electronic digital computers were the Colossus, built in England in 1943, and the ENIAC, built in the United States in 1945. However, the first special-purpose electronic computer may actually have been invented by John Vincent Atanasoff, a physicist and mathematician at Iowa State College (now Iowa State University), during 1937–42. (Atanasoff...

U.S. physicist. He received his Ph.D. from the University of Wisconsin. With Clifford Berry, he developed the Atanasoff-Berry Computer (1937–42), a machine capable of solving differential equations using binary arithmetic. In 1941 he joined the Naval Ordnance Laboratory; he participated in the atomic bomb tests at Bikini Atoll (1946). In 1952 he established the Ordnance Engineering Co.,...

any of a class of devices capable of solving problems by processing information in discrete form. It operates on data, including magnitudes, letters, and symbols, that are expressed in binary code —i.e., using only the two digits 0 and 1. By counting, comparing, and manipulating these digits...